BOSTON—Pregabalin reduced wake after sleep onset, compared with placebo and pramipexole, by 27.1 minutes and 26.9 minutes, respectively, according to research presented at the 26th Annual Meeting of the Associated Professional Sleep Societies. Pregabalin reduced the number of awakenings after sleep onset by 7.9, increased subjective total sleep time by 26.8 minutes, and increased slow-wave sleep by 32.1 minutes, compared with pramipexole.
Compared with placebo, pregabalin reduced patients’ International Restless Legs Scale (IRLS) score by six points, said Philip M. Becker, MD, Clinical Professor of Psychiatry at the University of Texas Southwestern Medical Center in Dallas. Compared with pramipexole, pregabalin reduced IRLS score by three points. Pregabalin also reduced periodic leg movements and arousals, compared with placebo and pramipexole. At baseline, patients taking pregabalin had 14 more leg movements per hour than patients taking pramipexole.
Pregabalin Versus Pramipexole and Placebo
Dr. Becker reported on pregabalin, pramipexole, and placebo in a randomized, double-blind, crossover study performed at 23 US sites. After a 10-day dose escalation period, equal numbers of patients took either 300 mg of pregabalin per day, 0.5 mg of pramipexole per day, or placebo for 19 days. Active treatment was followed by a taper and placebo washout period.
Eligible participants had an IRLS score of 15 or greater and had a score of 2 or higher on the IRLS item related to sleep. A total of 85 participants received at least one dose of study drug, and 62 subjects completed all aspects of the trial. Participants’ mean age was 55, and the three treatment groups were age-matched. About two-thirds of patients were female, and the onset of symptoms had occurred six years previously for most participants.
The study’s primary end point was a comparison of wake after sleep onset for pregabalin and placebo. The key secondary end points were periodic leg movements, arousal index, and subjective sleep time.
Adverse Events Were More Common With Pregabalin
Adverse events generally occurred during the first 10 to 14 days of treatment. Approximately 61% of patients receiving pregabalin had an adverse event, compared with 52% of patients receiving pramipexole and 37% of patients receiving placebo. About 5% of patients taking pregabalin discontinued treatment because of adverse events, compared with nearly 4% of patients receiving pramipexole.
The most common adverse events were dizziness (24%) and somnolence (17%), and these events caused several falls. About 8% of patients receiving pramipexole had somnolence, headache, or nausea.
“Pregabalin enhances sleep while treating restless legs syndrome,” said Dr. Becker. “One has to be aware of the dizziness and somnolence related to pregabalin and address that with patients. The adverse-event profiles are consistent with both products’ labeling for other disorders.”
—Erik Greb